Improvement in slide-valves for steam-engines



UNITED STATES PATENT Orricn.

REUBEN D. TURNER, OF NEX/V YORK, N.

IMPROVEMENT IN SLIDE-VALVES FOR STEAM-ENGINES.

Specitication forming part of Letters Patent No. 53,707, dated April 3, 1866,

` To all whom it may concern.-

Beit known that I, REUBEN D. TURNER, of the city, county, and State of NewYork, have invented a new and Improved Mode of Relievingthe Slide-Valves ot' Steam-Engines of Unnecessary Pressure; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l is a centrallongitudinal section of the valve-chest and slidevalve of a steam-engine illustrating my invention. Fig.l 2 is a transverse section ot' the same in the plane indicated by the line w in Fig. l.

Similar letters of reference indicate corresponding parts in both figures.

This invention consists in relieving the slidevalve of a steam-engine of unnecessaryY pressure by means of a properly-constructed hollow7 double-headed piston attached to the back ot' the valve, working in two cylinders provided within an inner valve-chest, and the interior of which forms a passage ot communication between the steam-chest or outer valve-chest and the induction-ports of the valve, while its exterior is unexposed to steam-pressure.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

A is the steam-chest or outer valve-chest, which resembles the valve-chest commonly used upon the cylinder of a locomotive-en gine, to both ends ot' whose cylinder the steam is inducted and educted by one slide-valve, except that it may require to be somewhat longer and deeper to provide room within it for the inner valve-chest, B, which is formed by constructing across it, near the ends, two partitions, c c, perpendicular to the valve-seat b, and uniting the said partitions by a transverse partition, a', parallel with the valve-seat, the said partition a', like those a a, extending entirely across the outer chest, A. In the two partitions, a a., there are constructed two cylinders, C C, one in each partition, the said cylinders being in line with each other and parallel with the valve-seat b.

The valve-seat b has in it the usual arrange ment of two steam-ports, cc, leading to opposite ends ot' the cylinder, and exhaust-port e, leading to the exhaust-pipe or condenser.

D is the slide-valve arranged within the inner valve-chest, B. This valve is of a wellknown kind, having two stean1-ports,cld, and an exhaust-cavity, f, between them, the said ports and cavity being so arranged that when either of the said ports is in communication with its respective port c in the seat b the other port c is in communication through the cavity fwith the exhaust-port e, as shown in Fig. 1.

The ports d d are in constant communication with the interior of the hollow double-headed piston E, which is cast with or otherwise rigidly secured to the valve. This piston is hollow throughout, and its heads gg are packed or otherwise fitted to worksteamtight'in the two cylinders, C G, 011e in each, while the face ot' the valve works steam-tight on the valveseat. The ends of the said piston are open and in free communication with the interior of the outer or steam chest, A, with which the inductioirpipe F of the engine is connected, so that when the engine is in operation the interior of the piston and the two valve-ports cl d are always filled with steam; but steam is excluded from the inner valve-chest, B, and consequently from the back ot' the valve, by mean-s of the packed piston-heads gg and the end portions, 71, 7L, of the valve, which extend beyond the ports d d, and the said valve-chest B has its interior in free communication with the atmosphere through openings i t' in its sides, so that the exterior of the back of the valve cannot be subject to pressure greater than that ot' the atmosphere. These openings i t' permit the escape of any possible accidental leakage of steam around the piston-heads int-o the inner chest, B.

The valve-stem lis attached to the piston E, and passes through the usual stuing-box at one end ot the valve-chest, and by giving motion to the piston gives motion also to the valves.

It has been explained how the back of the valve has the steam excluded from it, and it will be understood, as the whole exterior or periphery of the piston E is exposed to atmospheric pressure and th'e whole interior periphery of the said piston is exposed alike to steam-pressure, the stear would have no tendency to press the valve-down to its seat it' the ends of the said piston were finished in plane surfaces perpendicular to the axis; but,

on the contrary, the steam, acting on a portion What I claim as my invention7 and desire to secure by Letters Patent, is

The hollow piston E, cylinders C C, and inner valve-chest, B, in combination with each other and with the Valve D and outer chest, A, substantially as and for the purpose herein specified.

R. D. TURNER.

Witnesses: HENRY T. BROWN, J. W. GooMBs. 

